Hydraulic jack



P 1952 J. .1. MUELLER 2,610,025

HYDRAULIC JACK Filed Jan. 4,.1946 5 Sheet s-Sheet 1 J. J. MUELLER Sept. 9, 1952 HYDRAULIC JACK 5 Sheets-Sheet 2 Filed Jan. 4, 1946 Sept. 9, 1952 J. J. MUELLER 2,510,025

HYDRAULI C JACK Filed Jan. 4, 1946 5 Sheets-Sheet 3 5 50 5 v 360 w 563' 356 v 3'66 INVENTOR. MwZ

flt 4 5 Sheets-Sheet 4 J J MUELLER HYDRAULIC JACK QM %m \\m E MRM R gm M @h mm w Sept. 9, 1952 Filed Jan. 4, 19

Patented Sept. 9, 1952 UNITED STATES ATENT OFFICE HYDRAULIC JACK Joseph J. Mueller, St. Joseph, Mich, assig nor a Auto Specialties Manufacturing Company, St. Joseph, Mich, a corporation of Michigan Application January 4, 1946, Serial No. 639,015

a :7 6 Claims. 1

This invention relates to hydraulic jacks. The invention has been illustrated and described as most aptly applied to an hydraulic jack of the type known as floor jacks, but the invention has other hydraulic jack adaptations.

Among the objects of the present inventionis to provide an hydraulic jack wherein the pressure producing or pump mechanism comprises a relatively low pressure pump and a relatively higher pressure pump actuated from a common manually operated member, for creating a pressure in the ram cylinder; the arrangement being such as quickly to project the ram: cylinder to .a position such that the load lifting member is speedily brought to the work, at whichtime one of the pressure pump members, to-wit the low ing the foregoing constructions and characteristics and wherein theobject :of the invention is to provide mechanism for reciprocating two pumps from a single manual actuator, in a :compactly arranged manner.

Yet another object of the invention :resides in the arrangement of the relatively low ,andrelatively higher pressure pumps disposed in parallel relation with respect to thelongitudinal axis of the ram cylinder and at one end thereof, and in the intermediate disposition ofthe pressure relief valve for relieving the ram cylinder.

Other and further objects ofthe inventionwill be apparent from a perusal of the following specification, when taken in connection with the accompanying drawings, wherein:

Figure 1 is a perspective view showingthe various parts of the floor jack in a central relation; s

Figure '2 is a view showing certain of, theparts removed from the chassis and showinggthechassis itself; Figure 3 is a top plan view, partly in section, of the chassis;

Figure 4 is a section taken on the line .4-4

of Figure 3; v v

v I 2 Figure 5 is a section taken on line 5-7-5 of Figured; l

Figure 6 is a perspective view of the oscillating sector for the pump mechanism;

Figure 7 is a sectional view taken on the line 1-1 of Figure 5;

Figure 8 is a section taken on the line 8 8 o i ur and Figure 9 is a section taken through the rear end of the jack, and corresponding to Figure 4, and showing the work support in raised position. Referring now to the drawings in detail, the jack comprises a chassis shown particularly in Figure 2 which includes an enlarged body section vformedof two vertically disposed side plates 2 and 4 which at the forwardend are joined by a top plate 6 having a slight forward and downward inclination. This top plate 6 has two rearwardly extending ears 8 and it spaced apart and provided with registering perforations l2 and I 4 for the reception of a pivotal pin t6 hereinafter referred to. That section of the body portion to the rear of the top portion '6 is open at the top, as shown at ll. At this point the two side plates 2 and 4 are united by a rear transversely disposed wall [5 which in turn has a parallel extension in the form of vertical walls 16 and L8, and which are rigidly and integrally connected as at 2:0 by a top bridge portion for rigidity. These vertical side walls [6 and 18 are interconnected as at 22 by a transverse integral web which has a depressed cup-like cross groove 24 formed at the top thereof. The rearmost portion 26 of the body portion '22 is provided with registering openings for the reception of a stationary axle 30. -A threaded pin 32 holds the axle 3B in position on thechassis 2B. The opposite ends of theaxle 30 carry stationary shields 38 and 38 which are pinned thereto as at 39 and 4B, and casters or wheels 42 and A4 are rotatably mounted on the opposite ends of the axle .30.

On the underside thebody of the chassis is provided with two downwardly depending webs 46 and itil -for purposes of rigidity, and these webs are providedwi-th registering apertures which .extend parallel to and on the longitudinal axis of the chassis. Qneof these apertures such as 49 extends completely through the wallet while the aperture in the wall A16 is formed as a lcountersunk portion and is not formed completely through the wall. At the larger-end of the chassis the underface thereof is provided Witlrdovvm wardly depending partitional walls or :seats 53 and 1 12 which provide a mounting for a ram ,cyl

- 1y fits and lies within the webs 50 and 52.

inder, as shown in Figure 4. In other words, the underside of the chassis is substantially hollow except for certain of the rigidifying webs 46, 48, 50 and 52. The larger end of the chassis is provided with two integral outstanding shoulders 54 and 56, see Figure 3, each of which is provided with a vertical bore rotatably to receive each of which, as shown to the left in Figure 8, is a vertical bore rotatably to receive the turnable posts 58 and 60 of a caster wheel assembly comprising the ball bearing mounting 62 and the front shield 64 on which are mounted the axle 66 and rotatable caster 68. Means such as a pin I serves to hold the rotatable shank 58 of the casters in .position on the shoulders 55 and 51, permitting them to rotate but preventing their withdrawal.

As shown in Figure 2, the larger end of the chassis body below the top 6 is formed as a vertical flat front plate I2 carrying the relatively large opening or bore I4 in line with the high pressure pump cylinder hereinafter referred to. In addition this plate I2 is provided with four spaced apart threaded bolt holes 16 which are adapted to receive the bolts 80 which bolt on that part of the body portion 62 in which the high pressure pump cylinder, the pressure relief valve, and the various ball controlled liquid passages are formed. As shown in Figure 2, this high pressure pump cylinder head carries afiixed to it the ram cylinder 84 and its projecting ram 86. As shown in Figure 4, the ram cylinder snug- The body portion 82 includes the integral vertical plate member I5 from which the ram cylinder 84 projects. When the bolts 80 are tightened the vertical plate I5 of the body portion 82 is snugly tightened against the flat face I2 of the chassis, the ram cylinder 84 projecting into the opening E 4 of this end of the chassis.

A load lifting carriage hereinafter described as mounted upon the pivotal pin I 6, see Figure 9, passes through the perforated ears 8 and I0 of the chassis body 6 and also through a cross bore 96 of the downwardly extending section 98 of the load lifting member. This member has the two side flanges I00 and I02 which carry spaced apart bearing bores I04 and I06 adapted to receive a pin I 08 which carries a roller I I0. The elongated load lifting and lowering carriage 88 is shown in Figures 1, 2 and 9. It is provided with two vertical sides 90 and 92 and the transverse top 94. The forward end of this load carrying member 84, see Figure 2 is provided with two outstanding ears H2 and H4, which ears are perforated as at H6 and H8 to receive a pin I20, see Figure 1,

which supports a load liftinghead I 22. This head has a centrally disposed annular flange I24 receivable in a snugly apertured bore I26, the apertures of which receive the flange I24 of the load lifter I22 whereby the load lifter I22 may rotate as desired. The flange I26 is provided with two spaced apart ears I28 and I30 which are supported by the cross pin I20. In addition the flange I26 carries two lateral toes I32 and I34 which receive a cross pin I36 connecting to links I 88 and I39, the other ends of which are pivoted as at I40 to the side plates 2 and 4 of the chassis body. The purpose of these latter links is to maintain the rotatable work holder I22 in constantly horizontal postion. When the load is in lowered position it will rest within the grooved cross slot 24 of the chassis, whereby to enable it to nest in compact relationship.

As shown in Figure 4, a plunger I42 is supported by the member 98 and seats against a 4 shoulder I44 which is pivotally mounted on the pin I08. The plunger I42 is surrounded by a coil spring I46 and this spring has its opposite end retained in the cup-shaped recess of the cross web 46 as hereinbefore described. The purpose of this spring is such that when the ram piston 86 is projected from the ram cylinder against the roller IIO it will compress the spring I46 against its seat during the load lifting operation. Upon release of the ram piston, as hereinafter described, this spring will force the ram piston back into the cylinder and permit the load carrying member to lower. It is to be noted that this spring is disposed in the longitudinal central axis of the ram piston end 7 of the chassis.

By loosening the four screws (see Figures 1 and 2) the entire unit shown at the lower portion of Figure 2 may be removed from its seats 50 and 52 formed in the hollow inner walls of the chassis. As before noted, this unit comprises the body portion 82 and'the connected ram cylinder 84 carrying the ram 86. The plate I5 of the unit forms a shoulder I58v to receive thefront end of the upper wall 6 of the chassis. In addition, the body portion 82 is provided with a second shoulder I5I against which a sleeve I52 is clamped. The body portion 82 is provided with an extension I54 havingfla centralized concentric flange I56 threaded internally as at I58 and concentrically countersunk as at I60 to provide a central well. The ram cylinder I62 is likewise externally threaded on its rear end to engage thethreads I58 of the'fiange I56 so as to screw the ram cylinder in position and maintain it centralized with respect to the center line of the projection I54 on the body portion, 82. At its opposite end the ram cylinder sleeve I62 is externally threaded as at I64 to be engaged by the end sleeve I56; see Figure 4'. Tothis end the sleeve I56 is likewise internally threaded as at I 66'so that it engages the threads on the outer end of the ram cylinder I62 and this sleeve I56 is likewise provided'with a shoulder I66 against which the outer end of the reservoir cylinder 84 is clamped. The outer'end of the sleeve I56 is provided with a centralized countersunk portion I10 internally threaded as at I12 to. screw threadedly engage a packing ring I74 which maintains the packing H6 in position. By placing the ram cylinder sleeve I52 in position and screwing the ring-like cap I56 in place the concentric sleeves are firmly positioned and held to provide a hollow ram cylinder and a concentrically surrounding reservoir to hold the liquid for the hydraulic system.

Reciprocably mounted within the ram cylinder sleeve I62 is the ram piston '86. This'ram piston ,on its inner end is provided with a threaded centralized stem I18 of relatively small diameter. A ring nut I88 screws upon this stem I'IB to confine the usual type of sealing washer I82 and packing I84 between the shoulders formed on the body of thefram cylinder and the collar I80. The oppositeend of the ram cylinder 86 is relatively flat to engage the roller I I0, as hereinbefore described.-

Adjustable means is provided for relieving the pressure in the ram cylinder when the pressure reaches a predetermined maximum. This comprises the passage I86 formed in the body portion 82. The passage I86 communicates with an enlarged bore I88 which extends outwardly to the exterior. wall I90 of the boss formed on this head 82. This bore I88 is provided with a laterally extending, relatively smaller passage way 192 whichcommunicates as at I94 with the reservoir It-6. A ball valve [96 is adapted to seat. upon -a conical seat 266 formed at the junction of the bore 88 and the smaller passageway I86. Ihe cylindrical block 262 bears upon the ball Hi8. Thisblock has a stud 204 projecting from its opposite end and around which a coil spring 206 is con-fined, the opposite end of the coil spring bearing against a threaded plug 208- which engages internal threads of the outer end of the bore I88. This threaded plug has toolengaging portion 2 ill for turning. .A shank nut 2-I2 closes the terminal portion of this bore. By adjusting the position of the plug sea the pressureof the spring 206 isaccordingly adjusted to determine the pressure which-the ball ltd exerts upon the conical seat 62%. in effect determines the pressure by which the ball :may be forced outwardly by the liquid pressure in" the I addition, the ball valve cage block 242 .is provided ramcylinder so that a portion of the liquid 'may escape via the passage I92 back into the reservoir. V

The ram cylinder is provided with a so-called speed pump which is adapted quickly to get the ram up to the load to be lifted, and is likewise provided with a load lifting or pressure pump, which in the present instanceis relatively smaller than the speed pump for actually lifting the load once the load is contacted by the remand means 0 is provided for cutting out the speed pump so that the pressure pump alone'raises the load, and in addition means is provided for operating both of these pumps from a single actuator while permitting one of them to discontinue when the load noted that the ram cylinder is provided with a relatively large passageway 2I4 which connects with the well I60 of the ramcylinder. This passageway 2I4 merges into a bore 2I6 one end of which is provided with the conical walls 218 to which the bore 2l4 is centrally connected. At this conical end 2I-8 of the bore 2I'6 there is pro- ,vided a further, relatively smaller passageway 220 which connects as at 222 with the reservoir I96. .At the portion 224 the diameter of the bore 2'I6 is somewhat narrowed and is threaded as at 226. Outwardly of the internallythreaded portion 224 of the bore, such boreis provided with a shoulder 228. The bore 224 terminates at the point230 and the body or body portion 82, which has the side flanges 4H3 and '4l'8, provides a space therebetween which gives sufiicient clearance so that the speed pump cylinder 234 may be inserted in position as shown in Figure 7. This speed pump cylinder comprises the sleeve 234 externally threaded as at 236 at one end and provided at 238, centrally or intermediate its ends, with a polygonal angularly shaped portion, preferably a fouror sixfaced portiomfor turning. In addition the outer-end of the. sleeve is threaded as at 246. The inner end of the sleeve receives a combined valve cage and conical valve. The valve cage comprises a preferably metal block having an annular countersunk shoulder 242 providing an annular wall fitting frictionally tightly within the end of the speed pump sleeve 234. This block with a central passage 256 having a conical shaped valve seat controlled .by a ball valve2t3 which connects with a passage the opposite side of the ball valve cage. Inaddition thereis a third passage 254 in the .ball valve cage which passes therethrough from the face that connects with the pump cylinder 234 to a side port 260, hereinafter described. This passages254 is controlled by a third ball valve 256, spring :pressed normally to seat in the direction indicated inFigure 7. Asbefore stated, this passage 254 has a lateral passage 26!] which in turn communicates with a trans versely extending, relatively larger passage 252 formed in the body 82 and this passage likewise communicates with the enlarged bore 218. The outer face of the ball valve cage 26.6 .is provided with a countersunk portion .264 into which -frictionally fits a conical nose .265 having thecentral passage 268 which communicates with the passage 210 in turn communicating with the ram cylinder well I66. The relatively smaller portion of the conically shaped nose 266 seats upon the centralized aperture in the .conical valve seat 218 to close it, except for the passage 3.258. There is a packing 230 which surroundsthe threads .236 of the speed pump sleeve 234 and this packing is held in position by a ring 212. ...To the threads 240 of the outer end of thespeed pump sleeve is threaded a ring 216 provided with a central opening through which the speed pump piston 213 re ciprocates. The inner end of this pump piston is provided with the usual type of packing. The outer. end of the speed pump piston 218 is provided with a centrally located, threaded here 285 into which is threaded the shank of a bifurcated head 282 which receives through its bifurcation a cngss pin 284 hereinafter referred to, see Figure Spaced from the bore 224 for the speed pump cylinder formed in the body-portion 82 is another bore 236 which is of smaller diameter designed to receive the high pressure pump cylinder. This bore is conically fashioned as at 233 at its inner end and the central portion of this 'conically fashioned bore communicates as by means of a passage 29!! with the well it!) and'liirewise municates by means of a passage 292 with the reservoir Ifiii, and this bore 286 likewise cornmunicates by means of the cross passage 2:62 with the opposite bore 2H5 which houses the speed .pump. An inner portion 294 of this bore 26% is internally threaded and is likewise provided. with a countersunk portion 296 which receives'a packing 2%. This packing is held in position by a collar Sell engaging the external threads are of the pressure pump sleeve-like cylinder which is likewise externally threaded as at 38 and B86 and is preferably provided with an unthreaded portion 368 which is multi-sided to enable the sleeve to turn-to screw or unscrew it from its threaded bore 293 in the head Theouter end of the sleeve 362 receives ;-the packing til! held in place by the cap 3I2 engaging the external threads 366. A high'pressure pump piston 3l4 reciprocates through an opening in the collar 3 12 in the high pressure pump cylinder 316. The inner end of the high pressure pump cylinder 302 receives a ball valvecage 315 which has a first passageway 318 extending clearthrough from face to face. This passageway opens onto an enlarged bore terminating in the oppositeouter face of the cage 3l5. This enlarged bore 323 provided a conical seat in which a ball valve 32! rests and seats. In addition the cage 3l5 is provided with another passageway 324 which provides a conical seat against which the ball 326 seats and this passageway is provided with a lateral portion 328 opening onto'the bore 233. The cage is provided with a forward portion of smaller diameter 330 which frictionally seats within an inner wall of the high pressure pump cylinder 332. The outer end of the cage frictionally receives a conically shaped head 332 provided with a central passage 334 and a conical outer nose which seats upon the conical walls 238 hereinbefore mentioned to close'the same except for the central passageway 334' which passageway communicates with the passage 296 leading to the ram cylinder well I34, and the passageway 326 communicates by means of the centralized space between the outer end of the cage 315 and the inner face of the nose 332. This space in turn communicates with the passage 334. The outer end of the pressure pump piston 314 is internally threaded to receive the shank 333 of another bifurcated head 338 which head in turn receives the pin 284 in its bifurcations.

Centrally'of the two bores 2 I 6 and 236, the body portion 82 is provided with a central parallel extending bore 343. The bore 343 is provided'with a conical seat in turn provided with a relatively smaller passageway 344 which communicates with a diagonally extending passage346 which terminates as at 348 in the well I63. 'A' ball valve 336 normally seats'upon the conical relief valve seat and the position ofgthis ball valve 353 in turn is controlled by a plunger 352 'formedon the end of a release valve stem 354. This stem 354 is threaded as at 356 to engage internal 8 gether. In the registering holes 392 and 394 are located two pivotal pins or shafts 398 and 436 which are in axial registration. The outer ends of each of these pins are threaded to engage in openings 402 and 404 of the bosses 406 and 468 on the plates 4? and M2 of the head 15, see Figures 2 and 8. The pivotal pins 398'and 400 form the main pivot for the furcations M4 and M6 of the handle socket 4l8. This handle socket is provided with a boss 420 having an aper ture 422 to receive a locking shank 424 having a head 426. The boss is likewise provided with an annular countersunk 428 to receive a spring 436 surrounding the shank 424. The lower end of the shank 424 is provided with a locking shoe 432 which engages either of the notches 334 or 382, see Figure 6. By retracting the head 426 the shoe is disengaged from one notch andthen by swinging the socket M8 the other notches may be engaged. In this manner the actuator may be used for reciprocating the pistons while either in the vertical position as shown in Figure 5 or while disposed at an angle to the vertical position. It is to be noted that the universal 312 is disposed at the axis of turning 392 of the sectors. The socket 4l8 receives a sleeve 434. The furcations 313 of the pin 314 engagebetween a pin 436. This pin is formedon the inner wall of a sleeve 433 having a flange 446'forming an annular keyway 442. This sleeve 438 makes a tight fit with an elongated hollow handle 444 which turnably lies within the socket 4 I 8. Means is provided for holding the sleeve 438 and the handle 444 in position within the socket 4H). This comprisesa pin 446, see Figure 8,-having a head 443 and having a spring 456 which normally maintains the head Within the socket formed by the shoulder 44!] while permitting the sleeve 438 to be turned by turning the handle 434. However, when desired, by pulling outwardly on the head 448 the pin 446 "is moved outwardly, whereupon the handle 434 and the tight fitting sleeve 438 may be withdrawnfrom the handle socket, the pin 439 of the handle threads 353 on a threaded sleeve-like 'nut363 which threads into a'boss 332 on'the'head 32. Packing 364 is held inby the nut 363 and surrounds the shank 354 of the relief valve.' The relief valve shank 354 extends outwardly as at 333 and terminates in a head 338 of a universal connection 310 which connects as at 313 with another universal connection 312 in turn connected to a shank 314. This shank is bifurcated as at 316. It will be seen that the two pumps are spaced on each side of the central axis of the ram cylinder and that they lie in a common horizontal plane disposed below the horizontal plane passing through the central longitudinal axis of the ram cylinder. These two pumps are located to the rear of the ram cylinder. The release valve stem 366 is horizontally disposed and its central longitudinal axis lies in the common horizontal plane of the two pumps, substantially midway between the two pumps.

A manual actuator is provided for reciprocating the two pumps in the ram cylinder head 82. To this end a pair of sectors 318 and 330 are provided. Each of these sectors is provided with a pair of notches 382 and 384. In addition they are pinned together as by means of the pin 396. The sectors are provided also with registering apertures 392 and 394. In addition the pin 284 likewise assists in holding the sectors tofreely coming out from position between the furcations 316 of the rod or connector 314. When thus removed, the rod 314 is not accessible for turning. However when the handle and its sleeve with the cross pin 433 engages between the furcations of the rod, thenby turning the handle 434 the rod may likewise be turned, which, through the universal connection, turns a valve operating rod 366 to unscrewit from its seat and thereby permit the ball 342 to'be moved from its seat by pressure in the ram cylinder. The liquid will then flow from the ram cylinder through the passage 348, thepassageway 344, the ball 342, thence through the passage 343 to the reservoir, and the load member will thereupon lower. On the other hand, whenthe valve rod 352 forces the ball 34! to-its seat, and through the oscillation of the handle member and the sectors the high pressure pump piston 366 is operated, liquid willbe drawn from the reservoir through the passage292, thence into bore 263, thence through? passageway 328, past the ball 323 into the high pressure pump. Upon movement of the pump piston downwardly this liquid will then be forced through the passage 3l8, the ball 322, thence into passage 334, passage 296, into the ram cylinder, to move the ram outwardly of the ram cylinder.

In the operation of the complete device, starting with the jack in position under the load and with the load lever 88 in lowered position and liquid will be drawn by the pistonas it moves toward the right, see Figure 7, "from the reservoir through the port 220 to the space 218', thence through the lateral port 219, past the ball valve 2'48 into the speed pump cylinder chamber. Upon compression of this'same piston 218 this liquid. will flow through the port 25, past the ball valve 252, through the port 268 and port 214 into the ram cylinder chamber. When the ram has contacted the load and a predetermined pressure is created, the piston will then continue to operate, but due to the back pressure thus created in the ram cylinder being higher than the setting of the spring 2&5, any'liquid compressed in the speed pump chamber will be forced through the port 253., past the ball valve 255, out through lateral chamber 250, thence into the space 26L thence back through port 220 to the reservoir, and thus at this pressure the speed pump is thrown out of effective operation, and fromthen on the pressure pump 3 1'4 operates alone to raise the load in the manner hereinbefore described. In any event, the spring 206 of the pressure relief valve 98 can be set so that if the pressure created by the pressure pump in the well I60 becomes too great the pressure of theliquid will I force the spring 206 backward to permit the liquid to pass through the port I92 back into the reservoir.

Obviously the invention is not limited to the specific details of construction disclosed herein but is capable of other modifications and changes without departing from the spirit and scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is: l

l. A hydraulic jack comprising a body having means providing a ram cylinder and a reservoir, said body providing a ram cylinder chamberin association with said ram cylinder, a ramreciprocable in said ram cylinder, pumping means for drawing liquid from said reservoir and forcing it into said ramcylinderto cause said ram to raisea portion of the jack to engage the load,

said pumping means including a pump cylinder and a piston reciproc'able therein, said pump cylinder carrying avalve cage provided with a ported nozzle, means forming a passage interconnecting the port in said nozzle withsaid ram cylinder, means providing an annular chamber around said nozzle, means connecting said annular chamber with the reservoir, means providing a pair of additional liquid conducting passages in said valve cage, each of said passages interconnecting the pump cylinder chamber with said annular chamber, one of said passages being governed by a spring actuated relief valve adapted to be forced from its seat by the creation of a predetermined pressure in said pump chamber to pass liquid from said chamber back to the reservoir, and the other of said valves being adapted to be relieved from its seat to permit liquid to flow from said reservoir into said pump chamber, and a third valve controlling the passage interconnecting said pump chamber and the passage in saidnozzle,

said third valve closing said passage upon the creation of a predetermined pressure in said ram cylinder that is greater than in said pump chamber, a second pumping means comprising a relatively smaller diameter pumping cylinder, a relatively smaller piston reciprocable in said smaller diameter pumping cylinder, a second valve'cage carried by said second mentioned cylinderfla conical nozzle carried by said second cage, said nozzle having a valved passage connecting said pump chamber with said ram cylinder, means providing an'ann-ular passage surrounding said second conical nozzle, said second annular passag-e about said second nozzle connecting with the reservoir, and an additional passage formed in said second valve cage connecting said pump cylinder with said second annular passage, a valve, controlling said last mentioned passage, said valve being drawn from its seat upon the creation of asuction in the pump chamber, and

a release valve disposed between said pump cylinders, said release valve comprising a bore in saidbase, a common, passage connected to said release valve bore and to the annular passages surrounding the conical nozzles of the two pumps, said release valve bore communicating with the ram cylinder, a valve controlling said communication,,,,and a manually actuatable operating meansjto control said valve.

2.1m hydraulicjack comprising a base or chassis, forward and rearward pairs of wheels mounted on said chassis, a lifting lever pivotally mounted on said chassis and carrying a load support, said lifting lever having a power arm depending Within said chassis, the rear end of said chassis having an end opening provided with fastening means apertures adiacently disposed in spaced relation around said opening and a power unit comprising a substantially vertical plate having normally projecting from the face thereof an outwardly projecting ram cylinder and surrounding reservoir, there being a piston longitudinally slidable in" said ram cylinder, said plate having extending in the opposite directions at right angles thereto and in spaced relation on opposite-sides of the ram cylinder, parallel vertical plates disposed in spaced relation whereby when said first mentioned vertical plate isboltedto the rear, end of said chassis by means of fastening members passing through the spaced openings surrounding said main opening of the chassis the power unit is bolted in positionwith the end of the ram of the power unit confronting the depending end of the load lifting lever, said power unit including a pair of spaced pump cylinders formed in spaced bores in that end of the power unit that lies between the parallel spaced vertical plates and said vertical end plate, and a handle member having a yoked bottom por-- tion pivotally mounted in the opposed vertical plates of said power unit, said handle including depending armv portions having pivotal conneo tions with the outer ends of each of the pistons reciprocable in said pump cylinders, the body of the power unit between said pump cylinders being formed With a pressure relief valve bore communicating with the ram cylinder and a turnablepressure relief valve mounted in said i pressure relief valve bore, and said bore and tWo said turnable pressure release valve and said handle, one of said universal connections lying 11 in the pivotal axis of said handle, and turnable actuating connections carried by said handle for turning said pressure relief valve.

3. An hydraulic jack comprising a base or chassis, forward and rearward pairs of wheels mounted on said chassis, a lifting lever pivotally mounted on said chassis and carrying a load support, said lifting lever having a power arm depending within said chassis, the rear end of said chassis having an end opening provided with fastening means apertures adjacently disposed in spaced relation aroundsaid opening and a power unit comprising a substantially vertical plate having normally projecting from the face thereof an outwardly projecting ram cylinder and surrounding reservointhere being a piston longitudinally slidable in said ram cylinder, said plate having extending in the opposite directions at right angles thereto and in spaced relation on opposite sides of the ram cylinder, parallel vertical plates, said plates having registering bosses therein, a pair of stationary shafts supported in said bosses with the inner ends of said shafts disposed in spaced apart relation, a handle pivotally mounted on said shafts and a pair of interconnected sector arms likewise pivotally mounted on the inner end of said shafts, the adjacent end of the body of the power unit between said plates being formed with a pair of parallel bores disposed On opposite sides of the ram cylinder and slightly below the central longitudinal axis of the ram cylinder, said bores being located in a common horizontal plane, pump cylinders in said bores, one of said pump cylinders being larger than the other, pistons reciprocable in said pump cylinder and extending outwardly between said plates, said spaced sectors having connections therefrom to the pistons in said pump cylinders for actuating the latter on pivotal movement of said handle, the body of said power unit between the bores forming said pump cylinders being provided with an additional bore communicating with said ram cylinder, said bore lying in the same common plane with the bores of said pump cylinder, and a pressure relief valve turnably mounted in said bore, a turnable shaft mounted in said handle, and universal connections between said turnable shaft and the outer end of said release valve, one of said universals being disposed directly at the central axis of said pair of inwardly extending spaced apart shafts on which the handle is pivotally mounted.

4. An hydraulic jack comprising a body having means providing a ram cylinder and a reservoir, said body providing a ram cylinder chamber in association with said ram cylinder, a ram reciprocable in said ram cylinder, pumping means for drawing liquid from said reservoir and forcing it into said ram cylinder to cause said ram to raise a portion of the jack to engage the load, said pumping means including a pump cylinder and a piston reciprocable therein, said pump cylinder carrying a valve cage provided with a ported nozzle, means forming a passage interconnecting the port in said nozzle with said ram cylinder, means providing an annular chamber around said nozzle,- means connecting said annular chamber with the reservoir, means providing a pair of additional liquid conducting passages in said valve cage, each of said passages interconnecting the pump cylinder chamber with said annular chamber, one of said passages being governed by a spring actuated relief valve adapted to be forced from its seat by the creation of a predetermined pressure in said pump chamber to pass liquid from said chamber back to the reservoir, and the other of said valves being adapted to be relieved from its seat to permit liquid to flow from said reservoir into said pump chamber, anda third valve controlling the passage interconnecting said pump chamber and the passage in saidnozzle, said third valve closing said passage upon the creation of a predeter mined pressure in said ram cylinder that is greater than in said pump chamber, a second pumping means comprising a relatively smaller diameter pumping cylinder, a relatively smaller piston reciprocable in said smaller diameter pumping cylinder, a second valve cage carried by said second mentioned cylinder, a conical nozzle carried by said second cage, said nozzle having a valved passage connecting said pump chamber with said ram cylinder, meansproviding an annular passage surrounding said second conical nozzle, said second annular passage about said second nozzle connecting with the reservoir, and an additional passage formed in said second valve cage connecting said pump cylinder with said second annular passage, a valve controlling said last mentioned passage, said valve being drawn from its seat upon the creation of a suction in the pump chamber, a valve bore interconnecting said ram cylinder and the annular passages surrounding the conical nozzles of the two pumps, a release valve in said valve bore between said pump cylinders for selectively opening and closing said valve bore, and manual operating means to control said release valve.

5. An hydraulic jack comprising a base or chassis, forward and rearward pairs of wheels mounted on said chassis, a lifting lever pivotally mounted on said chassis and carrying a load support, said lifting lever having a power arm depending within said chassis, the rear end of said chassis having an end opening provided with fastening means apertures adjacently disposed in spaced relation around said opening and a power unit comprising a substantially vertical plate hav ing normally projecting from the face thereof an outwardly projecting ram cylinder and surrounding reservoir, there being a piston longitudinally slidable in said ram cylinder, said plate having extending in the opposite directions at right angles thereto and in spaced relation on opposite sides of the ram cylinder, parallel vertical plates disposed in spaced relation whereby when said first mentioned vertical plate is bolted to the rear end of said chassis by means of fastening members passing through the spaced openings surrounding said main opening of the chassis the power unit is bolted in position with the end of the ram of the power unit confronting the depending end of the load lifting lever, said power unit including a pump cylinder formed in a bore in that end of the power unit that lies between the parallel spaced vertical plates and said vertical end plate, and a handle member having a yoked bottom portion pivotally mounted in the opposed vertical plates of said power unit, said handle including a depending arm portion having pivotal connections with the outer end of the piston reciprocable in said pum cylinder, the body of the power-unit adjacent said pump cylinder being formed with a pressure release valve bore communicating with the ram cylinder and a turnable pressure release valve mounted in said pressure release valve bore, and said bore and pump cylinder being disposed in a common horizontal plane between said spaced parallel vertical plates, and universal connections between said turnable pressure release valve and said handle, one of said universal connections lying in the pivotal axis of said handle, and turnable actuating connections carried by said handle for turning said pressure release valve.

6. An hydraulic jack comprising a base or chassis, forward and rearward pairs of wheels mounted on said chassis, a lifting lever pivotally mounted on said chassis and carrying a load support, said liftinglever having a power arm depending within said chassis, the rear end of said chassis having an end opening provided with fastening means apertures adjacently disposed in spaced relation around said opening and a power unit comprising a substantially vertical plate having normally projecting from the face thereof an outwardly projecting ram cylinder and surrounding reservoir, there being a piston longitudinally slidable in said ram cylinder, said plate having extending in the opposite directions at right angles thereto and in spaced relation on opposite sides of the ram cylinder, parallel vertical plates, said plates having registering bosses therein, a pair of stationary shafts supported in said bosses with the inner ends of said shafts disposed in spaced apart relation, a handle pivotally mounted on said shafts and a pair of interconnected sector arms likewise pivotally mounted on the inner end of said shafts, the adjacent end of the body of the Power unit between said plates being formed with a bore disposed adjacent the ram cylinder and slightly below the central longitudinal axis of the ram cylinder, a pump cylinder in said bore, a piston reciprocable in said pump cylinder and extending outwardly between said plates, said spaced sectors having connections therefrom to the piston in said pump cylinder for actuating the latter on pivotal movement of said handle, the body of said power unit adjacent the bore forming said pump cylinder being provided with an additional bore communicating with said ram cylinder, said bore lying in the same common plane with the bore of said pump cylinder, and a pressure release valve turnably mounted in said bore, a turnable shaft mounted in said handle, and universal connections between said turnable shaft and the outer end of said release valve, one of said universals being disposed directly at the central axis of said pair of inwardly extending spaced apart shaits on which the handle is pivotally mounted.

JOSEPH J. MUELLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,610,499 Dybens Dec. 14, 1926 1,715,901 Countryman June 4, 1929 1,873,473 Pfauser Aug. 23, 1932 1,925,704 Pfauser Sept. 5, 1933 1,951,398 Dearsley Mar. 20; 1934 2,038,974 Werner Apr. 28, 1936 2,156,543 Pfauser May 2, 1939 

